On Sunday, a flash mob of 500 gathered in St. Petersburg to partake in an annual tradition: blowing bubbles to celebrate the arrival of spring.

This time, they were met by another mob, this one of 30 suspected neo-Nazis who thought the group was celebrating gay pride. (Get it? Bubbles are iridescent? Like rainbows?)

They descended on the bubble mob — known as “Dream Flash” or “Soapy Peter” — raining on their parade with fists and feet and rubber bullets. Two people were, apparently, injured.

Soon riot police arrived, screaming “Put away your bubbles!” They chased down the attackers, and then went after the bubble kids, detaining 30 of them for walking on the grass, a charge the bubblers deny.